Glove having butyl rubber layer to provide resistance to ketone family chemicals

ABSTRACT

A laminate of three layers includes a middle butyl rubber layer, whereas the inner layer and outer layer materials could be chosen from natural rubber latex, carboxylated acrylonitrile butadiene rubber latex, polychloroprene, polyisoprene, carboxylated styrene butadiene, and other synthetic elastomers. Even with one material used for both inner layer and outer layer, different formulations could be used. The resultant multilayer structure provides good resistance to ketone family chemicals such as acetone and MEK. The glove also exhibits superior or much improved resistance to solvent such as DMSO, chloroform, methanol, et al as compared to currently commercially available thin wall gloves made from natural rubber latex and carboxylated acrylonitrile butadiene synthetic rubber latex. The time elapsed before the material experiences breakthrough after exposure to a ketone family solvent is directly related to the thickness of the butyl layer.

BACKGROUND OF THE INVENTION

Gloves are used for their barrier characteristics to protect the wearerfrom chemicals and contamination. The structure and composition of theglove must be resistant to contamination to prevent contact with thewearer's skin. The structure and material of the glove can be tailoredto provide protection from anticipated contaminants.

Published patent applications disclose the structure of gloves resistantto solvents. One such published patent application is 2003/0075828 toThomas et al disclosing a solid resistant glove formed from multilayershaving an elastomeric substrate comprising nitrile rubber. Otherpublished patent applications, 2004/0036196 to Conley and 2004/0107477to Janssen, disclose surgical or medical gloves made from nitrile rubberand impermeable to many solvents. None of these published patentapplications discloses the use of different materials to enhanceresistance to chemical solvents and none uses a butyl layer to provideresistance to ketone family solvents.

It is an object of the invention to provide a material resistant toketone family solvents to be made into gloves.

Another object of the invention is to provide a multilayer glove havinga barrier layer of a material resistant to ketone family solvents.

It is another object of the invention to provide a glove made ofmultiple materials that can be made on existing equipment.

It is another object of the invention to provide a ketone familyresistant glove that is inexpensive to manufacture.

These and other objects of the invention will become apparent to one ofordinary skill in the art after reading the disclosure of the invention.

SUMMARY OF THE INVENTION

A laminate of three layers includes a middle butyl rubber layer, whereasthe inner layer and outer layer materials could be chosen from naturalrubber latex, carboxylated acrylonitrile butadiene rubber latex,polychloroprene, polyisoprene, carboxylated styrene butadiene, and othersynthetic elastomers. Even with one material used for both inner layerand outer layer, different formulations could be used. The resultantmultilayer structure provides good resistance to ketone family chemicalssuch as acetone and MEK. The glove also exhibits superior or muchimproved resistance to solvent such as DMSO, chloroform, methanol, et alas compared to currently commercially available thin wall gloves madefrom natural rubber latex and carboxylated acrylonitrile butadienesynthetic rubber latex. The time elapsed before the material experiencesbreakthrough after exposure to a ketone family solvent is directlyrelated to the thickness of the butyl layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of the laminate of the invention; and

FIG. 2 depicts the method of making the glove.

DETAILED DESCRIPTION OF THE INVENTION

A three-layered sandwich structure shown in FIG. 1 contains an outerlayer of nitrile rubber 10, a middle layer of butyl rubber 20 and aninner layer of nitrile rubber 30. This structure provides a resistanceto ketone family member solvents. It is possible that other layers ofother materials may be added or the three-layered sandwich structure maybe repeated.

The formulation of each layer is as follows: Nitrile Layers Butyl LayerBase 100 parts 100 parts Zinc Oxide 1 part 5 parts (Primary activator)Sulfur (crosslinker) 1 part 3 parts ZDBC (accelerator) 1 part 2 partsTitanium Dioxide 1 part 0 parts (optional) BHT (antioxidant) 1 part 1part Color pigment 0 parts 0 parts (optional)The base of the nitrile layer may be natural rubber latex or nitrile.Throughout the specification, the term ‘nitrile’ is used to encompassthese two materials. The base for the butyl layer is butyl latex.

Laminates made in accordance with the invention have demonstrated thefollowing resistance: Acetone Butyl layer Total film Breakthrough Samplefilm thickness, mm thickness, mm time, min Nitrile x 0.1˜0.12 1 1 ˜0.04˜0.1 15

MEK Butyl layer Total film Breakthrough Sample film thickness, mmthickness, mm time, min Nitrile x 0.1˜0.12 1 1 ˜0.02 ˜0.1 5 2 ˜0.04 ˜0.115 3 ˜0.06 ˜0.1 25 4 ˜0.09 ˜0.1 35

DMSO Butyl layer Total film Breakthrough Sample film thickness, mmthickness, mm time, min Nitrile x 0.1˜0.12 20 1 ˜0.04 ˜0.1 45 2 ˜0.07˜0.1 90 3 ˜0.1 ˜0.1 120

Chloroform Butyl layer Total film Breakthrough Sample film thickness, mmthickness, mm time, min Nitrile x 0.1˜0.12 1 1 ˜0.04 ˜0.1 5

Methanol Butyl layer Total film Breakthrough Sample film thickness, mmthickness, mm time, min Nitrile x 0.1˜0.12 50 1 ˜0.04 ˜0.1 >60, no BT at60, tested time up to 60 minutes.

The three-layered laminate structure is easily formed into gloves bydipping a form 32 into a first vat of nitrile rubber 34 to form a firstlayer, allowing that layer to cure, then dipping the form 32 having thefirst layer of nitrile rubber into a second vat having butyl rubber 36to form a middle layer and allowing the middle layer to cure. Finally,the form 32 is placed into a third vat having nitrile rubber 38 to formthe third layer. After final curing, the gloves are removed from theform 32. In the alternative, the form may be placed into the first vat34 to form the third layer, thereby obviating the need for a third vat.The glove has the advantage of being formed on existing machinery usingexisting methods.

While the invention has been described with reference to a preferredembodiment, various modifications would be apparent to one of ordinaryskill in the art without departing from the scope of the invention. Theinvention encompasses such various modifications.

1. A glove, comprising a first layer of nitrile rubber, a second layerof butyl rubber, and a third layer of nitrile rubber.
 2. The glove ofclaim 1, wherein said first layer is an inner layer, said second layeris a middle layer and said third layer is an outer layer.
 3. A method offorming a glove comprising dipping a form into nitrile rubber to form afirst layer, dipping the form into butyl rubber to form a second layer,and dipping said form into nitrile rubber to form a third layer.
 4. Themethod of claim 3, wherein said nitrile rubber and butyl rubber arestored in vats.
 5. The method of claim 3, wherein said form is dippedinto a first vat having nitrile rubber, then said form is dipped into asecond vat having butyl rubber, then said form is dipped into a thirdvat having nitrile rubber.
 6. The method of claim 3, wherein said formis dipped into a first vat having nitrile rubber, then said form isdipped into a second vat having butyl rubber, then said form is dippedinto said first vat.